That is pretty steep taking into account that even Postmark, which many consider expensive, charges only $1.50 per thousand emails. The basic plan is $3.33 for thousand and you're limited to specific daily limits... I usually don't complain about pricing but this just feels too much. Of course these two services are different but I chose Postmark as it's from the expensive end of email sending services. And one can replicate MailerJS in just one evening (when writing this there might already be a open source clone).

Enough with the whining... The main reason why I'm not a fan is that the pricing is hidden behind sign up and the site gives the impression that the service is free.